Surendra Singh Lilhore created HDFS-9355: --------------------------------------------
Summary: Support colocation in HDFS. Key: HDFS-9355 URL: https://issues.apache.org/jira/browse/HDFS-9355 Project: Hadoop HDFS Issue Type: New Feature Components: hdfs-client Reporter: Surendra Singh Lilhore Assignee: Surendra Singh Lilhore Through this feature client can give suggestion to HDFS to write his all the blocks on same set of datanodes. Currently this we can achieve through HDFS-2576. HDFS-2576 give option to hint namenode about favored nodes, but in heterogeneous cluster this will not work out. Support client wants to write his data in directory which have COLD policy, but he don't know which DN have ARCHIVE storage, So he will not able to give favoredNodes list. *Implementation* Colocation can enable by setting "dfs.colocation.enable" true in client configuration. If colocation is enable and favoredNodes list is empty then {{DataStreamer}} will set first set of datanodes as favoredNodes which is chosen for first block and subsequent block will use the same datanodes for write. Before closing file client can get the favoredNodes list and same he can use for writing new file. -- This message was sent by Atlassian JIRA (v6.3.4#6332)